The commercial harvest of Northern Fur Seals (Callorhinus ursinus)breeding on the Pribilof Islands in the Bering Sea has gone on with few interruptions for almost 200 years. Since 1910 this harvest has been carried out exclusively by the US federal government acting as an operating authority. At the same time the management of all Northern Fur Seals, those associated with Ostrov Tyuleniy [Robben Island] and Komandorskiye Ostrova [Commander Islands] as well as the Pribilofs, has been subject to the provisions of a series of international agreements dating back to 1911. These provisions also apply to small breeding populations of Northern Fur Seals on several of the Kuril'skiye Ostrova [Kuril Islands] and on San Miguel Island in the eastern North Pacific (US National Marine Fisheries Service, 1980, p 10–12). The most recent in this series, the Interim Convention for the Conservation of Northern Fur Seals of 1957, formally expired on 14 October 1980. But on the same date, the parties to the 1957 Convention (Canada, Japan, the Soviet Union and the United States) initialled a Protocol extending the Convention, with some minor modifications, for another four years. The Protocol is currently awaiting ratification by Japan and the United States, a process that may take some time. In the interim, the parties are proceeding under an informal agreement to act as though the Protocol were in force, although this may become increasingly difficult if ratification does not occur by the summer of 1981 when the next harvest would normally occur.

The fascination of the polar regions for the people of southern climes has always rested on the aura of mystery created by inaccessibility and the sense of prospective freedom offered by lands that were supposedly not claimed or utilized. Later, the intensive use of Arctic lands by their aboriginal inhabitants became clearer to those southerners who took the time to live for long periods in the Arctic, especially those whose opinions were open to the reality of what they observed around them. The Antarctic did not, of course, have a resident population to influence perceptions and has thus created a very different range of interests.

George VI Ice Shelf is about 450 km long, 20–70 km wide, and averages 250 m in thickness. It is bordered by Alexander Island to the west and by the Antarctic Peninsula to the east (Fig 1). The ice shelf is fed by glaciers flowing westwards from the Palmer Land plateau. In summer (November to late February) the ice shelf undergoes considerable surface melting and meltwater lakes form over an area of 4 500 km2 between 70°15′S and 72°00′S. The lakes and pools vary in size from a few centimetres deep and several square metres in area to a few metres deep covering areas of several square kilometres (Fig 2). Most of the lakes are characteristically elongate and ribbon-like and hence are termed ‘ribbon lakes’. From mid November to late February the lakes are a major obstacle to sledge parties travelling over the ice shelf.

Stream icings are a unique type of river ice that form in a portion of a stream channel which freezes deeply enough to restrict channel flow. Icings are usually found in Arctic and sub- Arctic regions because of the prevalence of permafrost and seasonally frozen ground in these regions. Hydraulic pressure builds up at the point of constriction as the river ice and permafrost thicken during the freeze-up period (Fig 1). Water is forced up through cracks in the river ice and freezes upon exposure to the cold air. This process continues in successive overflows until the source of water is exhausted.

One must suppose that even before Melville transformed the true story of an unusually lightcoloured Sperm Whale named Mocha Dick into his epic novel, Moby Dick, and certainly afterwards, whalers and zoologists working in the whaling industry have noted that pronounced morphological differences often exist among whales of the same species and stock (Lillie, 1915; Matthews, 1937; Pike, 1953). During the past 15 years, scientists studying living whales have commented on individuals with odd marks, scars, pigmentation patterns or albinism, deformities, algal films or the shape and position of external features such as the dorsal fin.